BEIJING (AP) — Chinese President Xi Jinping has demanded "decisive actions" against terrorism following an attack at a railway station in the far-west minority region of Xinjiang that left three people dead and 79 injured.

The bloodshed came as Xi wrapped up a four-day visit to the area that has witnessed rising violence against civilians and authorities blamed on radical Islamists and separatists.

The official Xinhua News Agency quoted eyewitnesses as saying at least two blasts went off at the South Station in the regional capital of Urumqi on Wednesday night, while a large group of knife-wielding attackers went after passengers.

"The battle to combat violence and terrorism will not allow even a moment of slackness, and decisive actions must be taken to resolutely suppress the terrorists' rampant momentum," Xi said in comments published on the front page of official newspapers Thursday and carried by state television.

There was no immediate word on arrests and it was unclear whether Xi was still in the region at the time of the attack. Information about events in the area about 2,500 kilometers (1,550 miles) west of Beijing is tightly controlled and was difficult to immediately verify any details.

"At the moment, it is acknowledged to be a terrorist attack. What is yet to be found out is who did this and for what purpose under whose instigation," Xinhua said in a report early Thursday.

Train service was suspended for about two hours, Xinhua said. It said security was tightened at all transport hubs in the city, which has a mainly Han Chinese population who are distinct from Xinjiang's native Turkic Muslim Uighur ethnic group.

A woman working at a convenience store near the train station said she heard a loud explosion shortly after 7 p.m.

"The whole area now has been cordoned off by police and military police," said the woman, who spoke by telephone and refused to give her name because of the sensitivity of the matter.

Photos circulating briefly on Chinese social media sites showed scattered luggage near the station's exit and a heavy presence of armed men. Xinhua said the blast was centered on some luggage left on the ground between the station's exit and a bus stop.

Tensions between Chinese and Uighurs have been simmering for years in Xinjiang, particularly since riots in 2009 in Urumqi left nearly 200 people dead. Beijing blames the violence on overseas-based instigators, but has offered little evidence.

Rian Thum, a professor at Loyola University in New Orleans, who specializes in Uighur history and issues, said the use of explosives to target civilians "would mark an alarming deviation from previous patterns of Uighur political violence."

"Most violent resistance had previously been directed at police officers, soldiers, and officials, often using knives and farm tools. The attack at the Urumchi train station, if it was carried out by Uyghurs, suggests an emerging pattern of more civilian targets and violence on a larger scale," he said.

Recent attacks appear to point to a greater level of organization and planning — along with continuing Chinese security and intelligence lapses despite massive growth in spending in those areas.

Last year, three Uighurs rammed a vehicle into crowds in a suicide attack near the Forbidden City gate in the heart of Beijing, killing themselves and two tourists.

In March, five knife-wielding men and women believed to be Uighurs slashed at crowds indiscriminately at a railway station in southwestern China, killing 29 people.

While Beijing faults separatists for raising ethnic tensions, government critics say restrictive and discriminatory policies and practices have alienated the Uighurs. They say Han people have flooded Xinjiang and benefited from its economic growth while Uighurs have felt excluded.

"The Urumqi explosion again proves that forceful repression is not a solution to the problem," said Dilxat Raxit, a spokesman for the World Uyghur Congress based in Germany.

During his visit to the region, Xi urged government officials to maintain social stability, promote growth, improve living standards and strengthen ethnic unity, according to state media reports.

Xi's visit dominated state broadcaster CCTV's evening news program Wednesday. It showed him shaking hands with police in helmets and bulletproof vests and inspecting shields and weapons used to quell riots.

"Local police stations are the fists and the daggers. We must work hard at the grass-roots level of the police stations," Xi said. "We must take care of our front-line offices. You need to protect yourselves and make achievements at tasks such as better serving the people in the future and safeguarding social stability."

Thum said Xi's description of local police as fists and daggers also fit "many Uyghurs' views of the police."

Xi told officials that the long-term stability of Xinjiang is vital to the whole country's reform, development and stability, Xinhua reported.